I have huge problems setting the font family and font size. I have tried just about everything with .MainMenu_MenuContainer, .MainMenu_MenuItem and .MainMenu_MenuItemSel - I can set the backgrounds and so on, but font-family, font-size and font-weight and color just don't work. Eg:

.MainMenu_MenuItem
{
    cursor: pointer;
    cursor: hand;
    color: #ffffff;
    font-family: Tahoma, Arial, Helvetica;
    font-size: 4px;
    font-style: normal;
}

This gives no results at all.
(No, I don't want to have 4px font, I just wanted to see if anything happens)

Now the menu in rendered html has this section:

FontStyle="font-family: Tahoma,Arial,Helvetica; font-size: 9pt; font-weight: bold; font-style: normal; text-decoration: "

Which I imagine overrides everything I try to do it in .css (what's the point of css again? :) ). Is there a way to disable this within the skin itself, without hacking the portal code? My main menu entry is:
<dnn:MENU runat="server" id="dnnMENU" />

Ok, I've found where my problem is. After doing this:

<dnn:MENU runat="server" id="dnnMENU" FontBold="false" FontSize="1" SeparateCss="true" />

The css seems to be working. Sorry for wasting your time.

An update. This is what was causing it to go wrong:
body, td, th
{
 font-family: georgia, "times new roman", serif;
 font-size: 12px;
 color: black;
}

This piece of css seems to be taking precedence. I'm guessing that the javascript renders the menu as tables. A nasty one to find this one.